BlockchainReader
Read-only provider for Cardano blockchain operations.
BlockchainReader provides read-only access to blockchain state without the ability to submit transactions. This is useful for:
- Snapshot-based testing where state should not be modified
- Transaction building that only needs to query UTxOs
- APIs that should not have submit capability
Use BlockchainProvider when you also need to submit transactions.
Implementations capture their ExecutionContext at construction time, so callers don't need to provide it for each method call.
Attributes
- Graph
-
- Supertypes
- Known subtypes
Members list
Value members
Abstract methods
Returns CardanoInfo for this reader.
Returns CardanoInfo for this reader.
This is always available synchronously after the reader is constructed. For emulators, this returns the current context. For remote providers like BlockfrostProvider, the CardanoInfo is fetched during async construction.
Attributes
Returns the current slot number.
Returns the current slot number.
Attributes
Returns the ExecutionContext captured by this reader.
Returns the ExecutionContext captured by this reader.
This is used internally by default method implementations. External code can use this when working with Futures returned by reader methods, or provide their own.
Attributes
Fetches the latest protocol parameters from the network.
Fetches the latest protocol parameters from the network.
Attributes
Find UTxOs using a type-safe query.
Find UTxOs using a type-safe query.
Value parameters
- query
-
The query specifying source, filters, and pagination
Attributes
- Returns
-
Either a UtxoQueryError or the matching UTxOs
Concrete methods
Find a single UTxO by its transaction input.
Find a single UTxO by its transaction input.
Value parameters
- input
-
the transaction input to look up
Attributes
- Returns
-
Either a UtxoQueryError or the found Utxo
Find UTxOs by a set of transaction inputs.
Find UTxOs by a set of transaction inputs.
Value parameters
- inputs
-
the transaction inputs to look up
Attributes
- Returns
-
Either a UtxoQueryError or the found UTxOs (fails if not all inputs are found)
Find all UTxOs at the given address.
Find all UTxOs at the given address.
Value parameters
- address
-
the address to query
Attributes
- Returns
-
Either a UtxoQueryError or the found UTxOs
Query UTxOs using lambda DSL.
Query UTxOs using lambda DSL.
This method translates a lambda expression to a UtxoQuery at compile time and returns a builder that can be further configured before execution.
Example:
// Simple query - execute immediately
reader.queryUtxos { u =>
u.output.address == myAddress
}.execute()
// With pagination and minimum total
reader.queryUtxos { u =>
u.output.address == myAddress && u.output.value.hasAsset(policyId, assetName)
}.minTotal(Coin.ada(100)).limit(10).execute()
Supported expressions:
u.output.address == addr- query by addressu.input.transactionId == txId- query by transactionu.output.value.hasAsset(policyId, assetName)- query/filter by assetu.output.value.coin >= amount- filter by minimum lovelaceu.output.hasDatumHash(hash)- filter by datum hash&&- AND combination||- OR combination
Value parameters
- f
-
Lambda expression from Utxo to Boolean
Attributes
- Returns
-
A UtxoQueryWithReader builder that can be configured and executed